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排序方式: 共有806条查询结果,搜索用时 15 毫秒
1.
A polystyrene-supported phosphine oxide-catalysed Beckmann rearrangement of ketoximes in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) has been developed. Good substrate compatibility, mild reaction conditions, good yields as well as the reusability of the catalyst/solvent made this procedure more environmentally benign. 相似文献
2.
Xiaomin Ren Miao Guo He Li Chengbin Li Liang Yu Jian Liu Qihua Yang 《Angewandte Chemie (International ed. in English)》2019,58(41):14392-14392
3.
Vanessa A. Béland Zhiqiang Wang Tsun-Kong Sham Paul J. Ragogna 《Journal of polymer science. Part A, Polymer chemistry》2022,60(16):2508-2517
In this work, we show that polymer networks composed of tertiary alkyl phosphines can be cleanly functionalized with phosphino-phosphonium or triphosphenium cations. Methods for functionalizing the polymers range from halide abstraction of commercially available reagents, to ligand exchange from simple to make reported compounds, and finally, macromolecular ligand design guided by observations made at the molecular level to accommodate the formation of kinetically favored triphosphenium cation functionalized networks. The synthesis, comprehensive characterization, and comparison of the new polymers to molecular analogues is outlined. It is shown the addition of the low valent phosphorus centers to the polymer network has the effect of tuning material physical properties. 相似文献
4.
A series of new heteromultinuclear FeI/RuII clusters are described. The complexes (η6-arene)RuFe2S2(CO)6 (arene = p-cymene 1 , C6Me6 2 ) and Fe2[μ-S (Cp*Ru)(CO)2]2(CO)6 (Cp* = η5-C5Me5) ( 3 ) were prepared by the reduction reactions of (μ-S)2Fe2(CO)6 with 2 equiv of LiHBEt3, followed by treatment (μ-SLi)2Fe2(CO)6 with ruthenium-arene complexes Ru2(μ-Cl)2Cl2(η6-arene)2 or Cp*Ru (CO)2Cl in 22–33% yields. Further reactions of 1 and 2 with 1 equiv of triphenylphosphine in the presence of the decarbonylating agent Me3NO·2H2O, afforded the corresponding monophosphine-substituted FeI/RuII complexes (η6-arene)RuFe2S2(CO)5(Ph3P) (arene = p-cymene 4 , C6Me6 5 ) in 75% and 78% yields. While treatment of parent complex 1 or 2 with 1 equiv of diphosphine Ph2PCH2PPh2 (dppm) in xylene at reflux temperature resulted in the formation of the diphosphine-bridged RuFe2S2(CO)9 derivate RuFe2S2(CO)7(dppm) ( 6 ). The possible pathway for the formation was proposed. Two isomers of novel macrocyclic complexes involve the (η6-arene) Ru-bridged quadruple-butterfly Fe/S clusters [{μ-S (CH2)3S-μ}{(μ-CS2)Fe2(CO)6}2]2[(η6-arene)Ru]2 (arene = p-cymene 7a and 7b , C6Me6 8a and 8b ) were isolated by reactions of two μ-CS2-containing dianion [{μ-S (CH2)3S-μ}{(μ-S=CS)Fe2(CO)6}2]2− with [Ru2(μ-Cl)2Cl2(η6-arene)2], in which the propylene groups are attached to two S atoms by ee and ea types of bonds respectively. All the new complexes 1 – 8 have been characterized by elemental analysis, spectroscopy, and particularly for 1 – 6 , 7b and 8a by X-ray crystallography. In addition, the electrochemical properties of representative complexes 1 – 4 and 6 have been investigated. 相似文献
5.
Arijit Ghorai Arun Kumar Mandal Susanta Banerjee 《Journal of polymer science. Part A, Polymer chemistry》2020,58(2):263-279
Sulfonated polytriazoles have drawn a great attention as high performance polymers and their good film forming ability. In the present study, a phosphorus containing new diazide monomer namely, bis-[4-(4′-aminophenoxy)phenyl]phenylphosphine was synthesized and accordingly, a series of phosphorus containing sulfonated polytriazoles (PTPBSH-XX) was synthesized by reacting equimolar amount of this diazide monomer (PAZ) in combination with another sulfonated diazide monomer (DSAZ) and a terminal bis-alkyne (BPALK) by the Cu (I) catalyzed azide–alkyne click polymerization. The polymers were characterized by nuclear magnetic resonance (1H, 13C, 31P NMR) and Fourier transform infrared spectroscopic techniques. The sulfonic acid content of the copolymers also determined from the different integral values obtained from the 1H NMR signals. The small-angle X-ray scattering results unfolded the well-separated dispersion of the hydrophilic and hydrophobic domains of the polymers. As a whole, the copolymer membranes displayed sufficient thermal, mechanical, and oxidative stabilities high with high proton conductivity and low water uptake that are essential for proton exchange membrane applications. The copolymers exhibited oxidative stability in the range of 15–24 h and had proton conductivity values were found as high as 38–110 mS cm−1 at 80 °C in completely hydrated condition. Among the all copolytriazoles, PTPBSH-90 (BPALK:DSAZ:PAZ = 100:90:10) having IECW = 2.44 mequiv g−1, showed proton conductivity as high as 119 mS cm−1 at 90 °C with an activation energy of 10.40 kJ mol−1 for the proton conduction. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 263–279 相似文献
6.
Dr. Alasdair I. McKay Dr. James Barwick-Silk Max Savage Prof. Michael C. Willis Prof. Andrew S. Weller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(13):2883-2889
The synthesis of rhodium complexes with weakly binding highly fluorinated benzene ligands is described: 1,2,3-F3C6H3, 1,2,3,4-F4C6H2 and 1,2,3,4,5-F5C6H are shown to bind with cationic [Rh(Cy2P(CH2)xPCy2)]+ fragments (x=1, 2). Their structures and reactivity with alkenes, and use in catalysis for promoting the Tishchenko reaction of a simple aldehyde, are demonstrated. Key to the synthesis of these complexes is the highly concentrated reaction conditions and use of the [Al{OC(CF3)3}4]− anion. 相似文献
7.
Maria De Fenza Anna Esposito Daniele DAlonzo Annalisa Guaragna 《Molecules (Basel, Switzerland)》2021,26(6)
The de novo synthesis of piperidine nucleosides from our homologating agent 5,6-dihydro-1,4-dithiin is herein reported. The structure and conformation of nucleosides were conceived to faithfully resemble the well-known nucleoside drugs Immucillins H and A in their bioactive conformation. NMR analysis of the synthesized compounds confirmed that they adopt an iminosugar conformation bearing the nucleobases and the hydroxyl groups in the appropriate orientation. 相似文献
8.
A Strategy to Control the Reactivation of Frustrated Lewis Pairs from Shelf‐Stable Carbene Borane Complexes 下载免费PDF全文
Dr. Yoichi Hoshimoto Takuya Kinoshita Prof. Dr. Masato Ohashi Prof. Dr. Sensuke Ogoshi 《Angewandte Chemie (International ed. in English)》2015,54(40):11666-11671
N‐Phosphine oxide substituted imidazolylidenes (PoxIms) have been synthesized and fully characterized. These species can undergo significant changes to the spatial environment surrounding their carbene center through rotation of the phosphine oxide moiety. Either classical Lewis adducts (CLAs) or frustrated Lewis pairs (FLPs) are thus formed with B(C6F5)3 depending on the orientation of the phosphine oxide group. A strategy to reactivate FLPs from CLAs by exploiting molecular motions that are responsive to external stimuli has therefore been developed. The reactivation conditions were successfully controlled by tuning the strain in the PoxIm–B(C6F5)3 complexes so that reactivation only occurred above ambient temperature. 相似文献
9.
Stefan Sander Dr. Robert Müller Dr. Mike Ahrens Prof. Dr. Martin Kaupp Prof. Dr. Thomas Braun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(57):14287-14298
The reaction of [PtCl2(COD)] (COD=1,5-cyclooctadiene) with diisopropyl-2-(3-methyl)indolylphosphine (iPr2P(C9H8N)) led to the formation of the platinum(ii ) chlorido complexes, cis-[PtCl2{iPr2P(C9H8N)}2] ( 1 ) and trans-[PtCl2{iPr2P(C9H8N)}2] ( 2 ). The cis-complex 1 reacted with NEt3 yielding the complex cis-[PtCl{κ2-(P,N)-iPr2P(C9H7N)}{iPr2P(C9H8N)}] ( 3 ) bearing a cyclometalated κ2-(P,N)-phosphine ligand, while the isomer 2 with a trans-configuration did not show any reactivity towards NEt3. Treatment of 1 or 3 with (CH3)4NF (TMAF) resulted in the formation of the twofold cyclometalated complex cis-[Pt{κ2-(P,N)-iPr2P(C9H7N)}2] ( 4 ). The molecular structures of the complexes 1–4 were determined by single-crystal X-ray diffraction. The fluorido complex cis-[PtF{κ2-(P,N)-iPr2P(C9H7N)}{iPr2P(C9H8N)}] ⋅ (HF)4 ( 5 ⋅ (HF)4) was formed when complex 4 was treated with different hydrogen fluoride sources. The Pt(ii ) fluorido complex 5 ⋅ (HF)4 exhibits intramolecular hydrogen bonding in its outer coordination sphere between the fluorido ligand and the NH group of the 3-methylindolyl moiety. In contrast to its chlorido analogue 3 , complex 5 ⋅ (HF)4 reacted with CO or the ynamide 1-(2-phenylethynyl)-2-pyrrolidinone to yield the complexes trans-[Pt(CO){κ2-(P,C)-iPr2P(C9H7NCO)}{iPr2P(C9H8N)}][F(HF)4] ( 7 ) and a complex, which we suggest to be cis-[Pt{C=C(Ph)OCN(C3H6)}{κ2-(P,N)-iPr2P(C9H7N)}{iPr2P(C9H8N)}][F(HF)4] ( 9 ), respectively. The structure of 9 was assigned on the basis of DFT calculations as well as NMR and IR data. Hydrogen bonding of HF and NH to fluoride was proven to be crucial for the existence of 7 and 9 . 相似文献
10.
《印度化学会志》2021,98(2):100023
The syntheses, structures and thermal reactions of [Ru3(CO)9{P(C4H3E)3}(μ-dppe)] (2, E = S; 3, E = O; dppe = 1,2-bis(diphenylphosphino)ethane) are described. These triphosphine-substituted clusters can be easily obtained in high yield from the Me3NO initiated room temperature reaction between [Ru3(CO)10(μ-dppe)] (1) and P(C4H3E)3. Both clusters have been structurally characterized which reveals that the functionalized phosphine P(C4H3E)3 is coordinated to the remote ruthenium atom using the phosphorus atom, while the NMR spectroscopic data indicate that both clusters are fluxional in solution mainly due to the ring-flipping process involving the dppe ligand which has been probed by VT NMR spectroscopy. Thermolysis of 2 at 66 °C affords 1 via P(C4H3S)3 dissociation, whilst that of 3 under similar experimental conditions also furnishes the diruthenium σ,π-furyl complex [Ru2(CO)6(μ,η2-C4H3O){μ-P(C4H3O)2] (4) in addition to 1. 相似文献